This invention concerns a conical screw connection for a multi-disk shaft coupling with a tension bolt, a first spring collet having a collar and arranged on the tension bolt, at least one second spring collet having a collar and supported by the first spring collet, so that disks of the multi-disk set can be secured on this second spring collet, with the seat between the tension bolt and the first spring collet being conical in shape and the seat between the first spring collet and the second spring collet being cylindrical in shape, and with a tension element clamping axially the disks of the multi-disk set, where the tension bolt has a threaded borehole for a screw whose head is supported on the tension element.
Such a conical screw connection is known from German patent application DE 196 25 318 A1. The tension element here consists of a nut which is screwed onto an outside thread provided on one end of the first spring collet, clamping the multi-disk set axially. On the outside, the nut is provided with grooves in which a suitable tool for tightening the nut can engage. Furthermore, the nut has a borehole through which is guided the screw, which can be screwed into the threaded borehole of the tension bolt and whose head is supported on the nut. After the disks of the multi-disk set placed between the collar of the second spring collet and the respective tension ring have been secured axially by tightening the nut, the screw provided for the tension bolt is tightened with another tool, pulling the tension bolt into the first spring collet and expanding it radially like the second spring collet, so that the ring of the multi-disk set is also clamped radially. This conical screw connection has proven essentially successful in practice.
The object of the present invention is to provide a conical screw connection which will permit optimal clamping of the multi-disk set while using the same tool for the axial and radial clamping of the disks.
This object is achieved with a conical screw connection of the type defined in the preamble by the fact that a force fit or a transition fit is formed between the tension bolt and the first spring collet in such a way that by tightening the screw, first the disks of the multi-disk set are clamped axially and then the spring collets are widened radially.
The conical screw connection according to the present invention is characterized in that the disks are first clamped axially by tightening the screw which is screwed into the threaded borehole of the tension bolt, so the disks are in tight contact and thus the prerequisite condition for optimum clamping of the multi-disk set is created. Then, by further tightening of the screw with the same tool, the tension bolt is pulled into the first spring collet, with both the first spring collet and the second spring collet arranged on the first being widened radially. Since the tool need not be replaced, this yields a simplified assembly.
In comparison with the conical screw connection known from German patent application DE 196 25 318 A1, the conical screw connection according to the present invention is also characterized by lower manufacturing costs, because it is no longer necessary to produce a thread on the first spring collet and the tension element clamping the disks axially. With the conical screw connection according to the present invention, the tension element can be clamped axially with respect to the second spring collet or the tension ring by means of the screw provided for the tension bolt.
The force fit or the transition fit of the conical screw connection according to the present invention is preferably formed by a cylindrical shoulder at the insertion opening of the first spring collet and by a cylindrical collar on the tension bolt, where the inside diameter of the cylindrical shoulder is slightly smaller than the outside diameter of the collar of the tension bolt. This design is simple and can be manufactured relatively inexpensively.
It is also advantageous if the depth of the shoulder is essentially equal to the width of the collar of the tension bolt. The maximum radial widening of the spring collets can be seen easily in this design, because in this condition, the end face of the tension bolt is flush with the end face of the first spring collet. Thus, a defined tightening of the conical screw connection can be ensured by monitoring the position of the end faces relative to one another.
According to a preferred embodiment, the tension element clamping the disks axially may have a base and a collar projecting beyond the base, said collar being supported on the collar of the second spring collet or a respective tension ring, and encompassing the end of the first spring collet with a radial clearance.
According to another preferred embodiment, the second spring collet may be provided with a tension ring, where the disks of the multi-disk set can be secured axially between the collar of the second spring collet and the respective tension ring.
For simple dismantling of the conical screw connection according to the present invention, it is advantageous if the tension bolt has another threaded borehole on the end opposite the first threaded borehole. The two threaded boreholes are preferably designed with the same dimensions. To dismantle the tension bolt clamped in the first spring collet, the screw threaded into the threaded borehole may be threaded into the opposite threaded borehole in combination with the tension element, with the tension element together with the screw then serving as an extractor tool.
The present invention is explained in greater detail below on the basis of a drawing illustrating one embodiment.